Improved Efficacy of Burdock-Loaded Nano-emulsion Gel in Acne Vulgaris Treatment by the Quality by Design Approach

Introduction: Acne vulgaris is a dermatological condition that significantly affects the physical appearance and quality of life of patients. The emergence of antibiotic resistance has com-promised the therapeutic efficacy of antibiotics in acne management. Burdock is a water-soluble bi-oactive agent that exhibits antimicrobial, anti-inflammatory, and antioxidant properties. Methods: Burdock was loaded into w/o/w nano-emulsion using the reverse titration method. The globule size, zeta potential, entrapment efficiency, and percentage cumulative drug release of the nano-emulsion were evaluated. The nano-emulsion was incorporated into a Carbopol 940 (0.5%, 1%, and 1.5% w/w) gel, and the drug permeability of the nano-emulsion gel was evaluated. The formula-tions of the nano-emulsion were optimized using the Box-Behnken design. Results: The Burdock was loaded into w/o/w nano-emulsion by applying the Quality by Design (QbD) approach considering the effect of the factors (phase volume ratio: PVR, time of primary emulsification: TPE, and concentration of Transcutol P: TLP) on globule size (GS) and % entrapment efficiency (%EE) of the drug. Discussion: The optimized nano-emulsion was prepared using Burdock and showed a GS of 176.2 nm and an EE of 99.1% with a PVR of 4.60, a TPE of 3.1 minutes, and a TLP concentration of 8.92%. Conclusion: The optimized nano-emulsion was transformed into a gel and characterized for mor-phology, viscosity, pH, drug content, in-vitro release, and ex vivo drug permeation. Finally, skin irritation study and histopathological evaluation suggested that the obtained nano-emulsion gel was effective in the treatment of Acne vulgaris.